Chromosones, DNA & Genes Flashcards Preview

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Flashcards in Chromosones, DNA & Genes Deck (16):
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Chromosomes

Thread-like structures
found in the nucleus of cells
made of DNA

1

Sister chromatids

Two identical chromosomes held together by the centromere that make up a duplicated chromosome

2

Human cells contain how many chromosomes?

46 chromosomes which form 23 pairs - one inherited from the father & one from the mother
(Apart from sex cells which have only 23 chromosomes)

3

Sex chromosomes

2 sex chromosomes in every human cell
XY ➡ in male cell
XX ➡ in female cell

4

DNA

A large molecule that makes up chromosomes and contains genetic information

5

Nucleotide

A unit of DNA made up of a phosphate, a sugar (deoxyribose) and a base

6

Bases in DNA

A (adenine)
T (thymine)
G (guanine)
C ( cytosine)

7

DNA pairings

A with T
G with C

8

A Gene

(a distinct sequence of nucleotides forming part of a chromosome)
that has the code for making a protein

9

The genetic code

The rules (code) by which the information encoded in the DNA sequence is translated into the amino acid sequence

10

How do bases code?

In groups of 3 - 3 bases code for 1 amino acid

11

Gametes

-Sex cells - sperm & egg
- they are haploid cells; have only 23 chromosomes

12

Why do red blood cells have no chromosomes?

Because they have no nucleus, giving them more space to carry oxygen

13

Pairs of matching chromosomes

Homologous pairs

14

Diploid cells

Cells with chromosomes in pairs

15

What does DNA stand for?

Deoxyrito nucleic acid